commendation vs recommendation

commendation

noun
  • The act of commending; praise; favorable representation in words; recommendation. 

  • That which is the ground of approbation or praise. 

  • A message of affection or respect; compliments; greeting. 

  • An award or recognition for performance; a medal. 

recommendation

noun
  • A commendation or endorsement. 

  • An act of recommending. 

  • A suggestion or proposal about the best course of action (with adpositions including "about" for the context and "to" for the course of action) 

  • That which is recommended. 

How often have the words commendation and recommendation occurred in a corpus of books? (source: Google Ngram Viewer )